2  Population and health geography

2.0.1 Definition

• Population geography studies the spatial distribution, density, and dynamics of human populations.
• Health geography examines the spatial patterns of health, disease, and healthcare access.

2.0.2 Why it matters

• World population surpassed 8 billion in 2023 (UN estimate).
• Uneven distribution of population and healthcare creates social and economic challenges.
• Population change influences urbanization, economic growth, and environmental sustainability.

2.0.3 Fundamental Questions in Population Geography

• Where do people live? (Population distribution & density)
• How is the population changing? (Growth, decline, migration)
• Why do these changes happen? (Fertility, mortality, economic & social factors)
• How do population changes affect resources and policies?

2.1 Understanding Population Distribution

2.1.1 Global Population Distribution

Uneven Distribution:

• 90% of the world’s population lives in the Northern Hemisphere.
• Most people live near coastlines, rivers, and fertile land.
• Only ~30% of Earth’s land is habitable for dense populations.

Factors Influencing Population Distribution:

2.1.1.1 Physical Factors

• Climate (e.g., dense populations in temperate regions).
• Land-forms (e.g., river valleys vs. deserts).
• Natural resources (e.g., oil-rich regions).

2.1.1.2 Human Factors

• Political stability and governance.
• Economic opportunities (e.g., industrial hubs).
• Cultural and historical reasons (e.g., religious sites).

2.1.1.3 Case Study: Population Density in Asia

China and India account for 35% of the world’s population due to:

• Fertile lands (Ganges & Yangtze river valleys).
• Monsoon climate supporting agriculture.
• Historical urbanization and trade centers.

2.2 Population Growth and Decline

2.2.1 Measuring Population Growth

Crude Birth Rate (CBR): Number of births per 1,000 people per year.

Crude Death Rate (CDR): Number of deaths per 1,000 people per year.

Natural Increase Rate (NIR):

• Formula: NIR = CBR - CDR
• If NIR > 0, population grows; if NIR < 0, population declines.

2.2.1.1 Demographic Transition Model (DTM)

A model explaining how populations change over time in response to economic and social progress.

Stage	Characteristics	Example Countries
1: Pre-Industrial	High birth & death rates, slow growth	Isolated tribes (Amazon, Congo)
2: Early Industrial	Declining death rate, high birth rate, rapid growth	Nigeria, Afghanistan
3: Late Industrial	Declining birth rate, slower growth	Mexico, India
4: Post-Industrial	Low birth & death rates, stable growth	USA, Canada
5: Declining	Low birth rate, aging population, negative growth	Japan, Italy

Example: Japan’s Aging Population (Stage 5)

• Population shrinking due to low fertility rate (1.3 children per woman).
• Impacts: Labor shortages, rising healthcare costs, increased retirement age.
• Government response: Encouraging immigration and family-friendly policies.

2.3 Fertility, Mortality, and Migration

2.3.1 Factors Affecting Fertility Rates

High Fertility Rates (Developing Countries)

• Limited access to contraception.
• Cultural/religious preferences for large families.
• Rural economies dependent on children for labor.

Low Fertility Rates (Developed Countries)

• Economic cost of raising children.
• Increased education and employment for women.
• Urbanization reducing family size.

2.3.2 Causes of Mortality (Death Rates)

• Infant Mortality Rate (IMR): Deaths of infants <1 year per 1,000 live births.
• Life Expectancy: Average lifespan of a population.

Example: Sub-Saharan Africa (High Mortality)

• Leading causes: Malaria, HIV/AIDS, malnutrition, lack of healthcare.
• Efforts to reduce: Vaccination programs, improved sanitation, healthcare funding.

2.3.3 Migration Patterns

• Push Factors (forcing people to leave): War, poverty, natural disasters.
• Pull Factors (attracting people): Job opportunities, political stability, better education.

Examples of Large-Scale Migrations:

• Syrian Refugee Crisis (2011–present): Millions fleeing war.
• Rural-to-urban migration in China: 300 million+ people moving to cities.

2.4 Health Geography

2.4.1 What is Health Geography?

Examines how location affects health and disease spread.

Key topics:

• Epidemiology (disease spread).
• Healthcare access and inequalities.
• Environmental health risks.

2.4.2 Disease Patterns and Epidemics

• Endemic: Constantly present in a population (e.g., malaria in Africa).
• Epidemic: Sudden outbreak in a region (e.g., Ebola in 2014).
• Pandemic: Global outbreak (e.g., COVID-19).

Example: COVID-19 Pandemic (2020–Present)

• Origin: Wuhan, China.
• Spread: Global air travel, urban density.
• Impact: Healthcare strain, lock-downs, economic crisis.

Role of Geography:

• GIS mapping for tracking cases.
• Urban density affecting transmission.
• Global cooperation in vaccine distribution.

2.4.3 Healthcare Access and Inequality

• Developed Countries: Universal healthcare, advanced hospitals.
• Developing Countries: Poor access, high disease rates.

Example: Healthcare Disparities in the USA

• Urban areas have better hospitals vs. rural regions with limited access.
• Minority groups have higher infant mortality and lower life expectancy.

2.5 Key takeaways

• Global population is unevenly distributed.
• Fertility and mortality rates shape population trends.
• Health geography is critical for disease control and healthcare policy.